Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.2.13 (aldolase)
 3,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Enzymes that mediate carbanion chemistry must protect their reactants from solvent and undesirable electrophiles, such as molecular oxygen. A number of enzymes that utilize carbanionic intermediates were surveyed for O2-consuming side reactions. Several of these enzymes, acetolactate synthase, pyruvate decarboxylase, class II aldolase, and glutamate decarboxylase, catalyze previously undetected oxygen-consuming reactions, while others such as class I aldolase, [(phosphoribosyl)amino]imidazole carboxylase, 6-phosphogluconate dehydrogenase, isocitrate dehydrogenase, and triosephosphate isomerase do not. Prior to this work, only ribulosebisphosphate carboxylase was known to catalyze an oxygenase side reaction. These new example indicate that while O2-consuming side reactions are a more general feature of enzyme-mediated carbanion chemistry than has been previously appreciated, they are not necessarily an inevitable consequence of this chemistry. Expression of an oxygenase activity not only depends on the accessibility of the carbanionic intermediate to molecular oxygen but also may depend on the ability of the enzyme to stabilize the initially formed peroxide anion either through protonation with an appropriate enzymic group or through metal coordination.
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PMID:Oxygenase side reactions of acetolactate synthase and other carbanion-forming enzymes. 186 63

Within the framework of an international project on the sequencing of the whole Bacillus subtilis genome, a 15 kb chromosome segment, which contains the iol operon involved in inositol utilization, has been cloned and sequenced. This region (14,974 bp) contains 12 complete open reading frames (ORFs; genes) and two partial ones; the seventh gene (E83G) is the idh gene encoding inositol dehydrogenase. All the genes identified are transcribed in the same direction as that of the movement of the replication fork. A homology search for their products deduced from the 12 complete ORFs revealed that eight of them exhibit significant homology to known proteins such as fructokinase, acetolactate synthase, fructose-1,6-bisphosphate aldolase (B. subtilis), and PhoB and FtsE proteins (Escherichia coli). It also implied that two genes (B65D and B65E) might encode a set of two-component regulatory proteins and that the B65F gene might encode a protein belonging to the ATP-binding cassette (ABC) family. Based on the features of the nucleotide sequence determined and the results of the homology search, the primary structure of the iol operon is predicted.
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PMID:Cloning and nucleotide sequencing of a 15 kb region of the Bacillus subtilis genome containing the iol operon. 795 81

To examine the effects of N nutrition upon endosperm development, maize (Zea mays) kernels were grown in vitro with either 0, 3.6, 7.1, 14.3, or 35.7 millimolar N. Kernels were harvested at 20 days after pollination for determination of enzyme activities and again at maturity for quantification of storage products and electrophoretic separation of zeins. Endosperm dry weight, starch, zein-N, and nonzein-N all increased in mature kernels as N supply increased from zero to 14.3 millimolar. The activities of sucrose synthase, aldolase, phosphoglucomutase, glutamate-pyruvate transaminase, glutamate-oxaloacetate transaminase, and acetolactate synthase increased from 1- to 2.5-fold with increasing N supply. Adenosine diphosphate-glucose pyrophosphorylase and both ATP- and PPi-dependent phosphofructokinases increased to lesser extents, while no significant response was detected for hexose kinases and glutamine synthetase. Nitrogen-induced changes in enzyme activities were often highly correlated with changes in final starch and/or zein-N contents. Separation of zeins indicated that these peptides were proportionately enhanced by N supply, with the exception of C-zein, which was relatively insensitive to N. These data indicate that at least a portion of the yield increase in maize produced by N fertilization is induced by a modification of kernel metabolism in response to N supply.
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PMID:Response of enzymes and storage proteins of maize endosperm to nitrogen supply. 1666 63